29 states and Wash DC have an RPS, which require utilities to source a certain percentage of energy from renewables by a target date (the percentage and target date varies greatly between states).

With the addition of another 60 GW of renewable energy capacity, all states with RPSs will have met their goals.

"The cumulative amount of new capacity required is fairly significant, at least related to what's in place today, but the actual pathway and ramp rate required to get there doesn't require a huge amount of stretching, at least at a gross national level," says Galen Barbose, a LBNL staff research associate. "The actual ramp rate required to get there is in fact well within the pace we've been adding renewables within past couple years."

Unfortunately, the introduction of new RPS initiatives has significantly slowed and most states haven't upped their targets as they close to meeting them.

Although ALEC views state RPSs as a tax on consumers that unfairly mandates some energy sources over others, LBNL's research shows that electric rates have risen less than 5%. In fact, states that have an RPS report the costs of renewable energy are dropping.

This map, from the US Energy Information Administration, shows the significance of an RPS - it shows the growth of non-hydro renewables in states with and without an RPS.